A fixing device including a belt is known in the art. Such conventional fixing device includes an endless belt, a nip member provided in an internal space of the endless belt, and a pressure roller providing a nip region in cooperation with the nip member. The endless belt includes an elementary tube made from metal, and a coating layer formed over an outer surface of the elementary tube and made from fluorine contained resin.
Japanese Patent Application Publication No. 2007-249186 discloses a fixing device having an endless belt in which an outer surface of the elementary tube is subjected to blasting in order to increase bonding strength between the elementary tube and the coating layer. Further, thus publication also discloses an endless belt in which each end region of the elementary tube in a longitudinal direction thereof is subjected to masking so that an outer peripheral region of the elementary tube including a central region and other than each end region can be subjected to blasting.